Part B · 2026
Part B late enrollment penalty calculator
See how a delay changes the monthly premium, then check whether creditable coverage or a Special Enrollment Period can keep the penalty off your record.
Last updated
Written and maintained by Abdul SamadPunjab, Pakistan
| Penalty rate | 10% per full yearOnly full 12-month periods count. |
|---|---|
| Standard premium, 2026 | $202.90The penalty is a percentage of this amount. |
| One-year penalty | $20.29/monthAdds $243.48 a year. |
| Special Enrollment Period | 8 monthsUsually after active employer coverage ends. |
| Is the penalty permanent? | Generally yesIt stays while you have Part B, unless SSA corrects it. |
Your result
Part B penalty estimate
Penalty applies. Monthly penalty $40.58. Total monthly premium $243.48.
Each full 12-month period adds 10% of the standard premium. Your estimate adds $40.58 a month to the $202.90 standard premium.
Longer view
| 10-year penalty total | $4,869.60 |
|---|---|
| 20-year penalty total | $9,739.20 |
| Full 12-month periods | 2 |
The penalty is generally permanent while you have Part B. The 10-year and 20-year totals are planning views, not a statement that you must keep Part B for that long.
Can you avoid it?
Creditable coverage can help you qualify for a Special Enrollment Period, but it does not erase a delay that already happened. Confirm your dates with Social Security.
You indicated creditable coverage. Keep the plan notice that confirms it and the exact start and end dates.
Show the math
- Full 12-month periods: 24 months ÷ 12 = 2 full periods.
- Penalty rate: 2 × 10% = 20%.
- Monthly penalty: $202.90 × 20% = $40.58.
- Total monthly premium: $202.90 + $40.58 = $243.48.
- 10-year penalty total: $486.96 × 10 = $4,869.60.
- 20-year penalty total: $486.96 × 20 = $9,739.20.
What to do next
- Confirm your exact dates with Social SecurityAsk for the month your Initial Enrollment Period ended, the month you enrolled, and the months Social Security counted. A one-month date error can change the penalty.
- Keep proof of creditable coverageAsk the employer or plan for a written creditable coverage notice showing the start and end dates. Do not rely on a verbal answer.
- If a Special Enrollment Period applies, enroll nowThe usual window is eight months after active employer coverage ends. Gather the employer coverage end date and submit the Part B application before the window closes.
Scenario compare
Change one fact to see how the answer moves. The alternate column uses the same rules and the same sources.
| Result | Current | Alternate |
|---|---|---|
| Full 12-month periods | 2 | 1 |
| Monthly penalty | $40.58 | $20.29 |
| Total monthly premium | $243.48 | $223.19 |
| 20-year penalty total | $9,739.20 | $4,869.60 |
Deadline and timing
If you are leaving active employer coverage, the usual Special Enrollment Period lasts eight months after that coverage ends. The General Enrollment Period runs January 1 through March 31 each year for people who missed their first chance.
A result can be right for the inputs and still be wrong for your state or tax household.
Report an error in this calculatorHow much is the Part B penalty
The Part B penalty is 10% of the standard premium for each full 12-month period you did not have Part B and did not have creditable coverage. A delay of 11 months adds nothing under this rule because it is not a full 12-month period.
At the 2026 standard premium of $202.90, one full year adds $20.29 a month. Two full years add $40.58 a month. The penalty is added to the standard premium, not charged as a separate bill.
Part B penalty 10 year cost
A one-year delay adds $2,434.80 over 10 years at the current premium. This is a planning view: it multiplies the annual penalty by 10 and does not assume future premium increases or changes in your coverage.
Part B penalty 20 year cost
The same one-year delay adds $4,869.60 over 20 years at the current premium. A two-year delay is larger because the penalty rate is 20% instead of 10%.
How is the Part B penalty calculated
First, count only full 12-month periods. Second, multiply that number by 10%. Third, multiply the result by the current standard premium. Finally, add the penalty to the standard premium to get the total monthly amount.
Social Security may round the final premium, so the official amount can be a few cents different from the unrounded math shown here.
Can I avoid the Part B penalty
You may avoid the penalty if you qualify for a Special Enrollment Period or another recognized exception. Active employer coverage based on current employment is the most common path, but the plan must be creditable and the enrollment window still matters.
COBRA and retiree coverage usually do not create the same eight-month Special Enrollment Period. Do not delay Part B just because you have COBRA. Confirm the rules with Social Security and the employer plan before the window closes.
What changed for 2026 compared with 2025
| Rule | 2025 | 2026 |
|---|---|---|
| Part B standard premiumThe penalty is recalculated against the current standard premium. | $185.00 | $202.90 |
| One full-year penalty10% of the standard premium. | $18.50 | $20.29 |
| Part B deductibleNot part of the penalty, but part of the Part B cost picture. | $257.00 | $283.00 |
Worked example
A person delayed Part B for 24 months without creditable coverage. The delay includes two full 12-month periods, so the penalty rate is 20%.
| Months delayed | 24 |
|---|---|
| Full 12-month periods | 2 |
| Penalty rate | 20% |
| Monthly penalty | $40.58 |
| Total monthly premium | $243.48 |
| 10-year penalty total | $4,869.60 |
| 20-year penalty total | $9,739.20 |
The unrounded math here shows $243.48. Social Security may round the final premium by a few cents.
MedicareClear is independent. We do not sell plans, rank carriers, or claim an official connection to Medicare.gov or any government agency.
Three honest caveats
- The penalty depends on your exact enrollment dates. This calculator asks for months, but Social Security uses the month you were first eligible to enroll and the month your coverage actually started.
- Creditable coverage is a plan fact, not a guess. Ask the employer or plan for a written notice and keep it with your Medicare records.
- This is an educational estimate. It does not decide a Special Enrollment Period or an exception. Social Security makes the final decision, and the premium can change when the standard premium changes.
Frequently asked questions
Medicare Part B penalty per month
At the 2026 standard premium of $202.90, one full 12-month period adds $20.29 a month. The penalty is 10% of the standard premium for each full 12-month period without creditable coverage.
Part B special enrollment period 8 months
If you had active employer coverage based on current employment, you generally have eight months after that coverage ends to enroll in Part B without a penalty. The eight-month clock can start before COBRA or retiree coverage ends, so confirm your dates with Social Security.
Part B creditable coverage exemption
Creditable coverage can let you delay Part B without a penalty while you are still covered by the employer plan. The coverage must be at least as good as Medicare for the benefit you delayed, and you usually need the plan's written creditable coverage notice.
What is the Part B penalty for 2026?
The penalty is 10% of the 2026 standard premium for each full 12-month period. At $202.90 a month, one full year is $20.29 a month, or $243.48 a year. The dollar amount changes when the standard premium changes.
Does the Part B penalty ever go away?
The penalty generally stays with you for as long as you have Part B. It is not a one-time fee. If you believe the penalty is wrong because of an employer coverage error or a qualifying event, ask Social Security to review the decision.
How do I appeal a Part B penalty?
Start with Social Security and ask for the dates and coverage information used in the decision. Provide the employer coverage end date, the creditable coverage notice, and any Special Enrollment Period proof. Ask what review or appeal step applies to your case.
Related help
Source table
| Figure | Value used | Official source |
|---|---|---|
| Part B penalty rate | 10% per full 12-month period | Medicare.gov late enrollment penaltiesChecked |
| Part B standard premium | $202.90 | CMS Part B premium fact sheetChecked |
| Special Enrollment Period | 8 months after active employer coverage ends | Medicare.gov sign-up rulesChecked |
| General Enrollment Period | January 1 through March 31 each year | Medicare.gov late enrollment penaltiesChecked |
| Creditable coverage | Written plan notice required | Medicare.gov sign-up rulesChecked |
Cite this page
If you cite this page, use the reference below. It shows the date the figures were last checked so readers can judge whether they are current.
MedicareClear. “Part B late enrollment penalty calculator.” Figures checked October 28, 2026. https://medicareclear.top/calculators/part-b-late-enrollment-penalty
Print the checklist for a parent or keep a copy for your records. If a figure looks wrong, send the page and the official source you used.
Found a mistake?Report an error
MedicareClear is independent and is not connected to Medicare.gov, Social Security, or any government agency. This page is educational and does not provide legal, tax, or insurance advice. Confirm your enrollment dates and coverage with Social Security before you act.
Last updated